Fuel distributor



Jan.' 9, 1945. F J, WIEGAND 2,366,891

FUEL DISTRIBUTOR l Filed Oct. 27, 1942 l 2 Sheets-Sheet l INVENTOR Fnmczs :l WIL'GAND.

A T TORNE Y Jan. 9, 1945. F. J. WIEGAND 2,366,891.

FUEL DISTRIBUTOR Filed Oct. 27, 1942 2 Sheets-Sheet 2 IN VE N TOR FRANCIS I wmansm TT ORNE Y Patented Jan. 9, 1945 Francis J. Wiegand, Ridgewood, N. J., assignorto WrightAeronautical Corporation, a corpo ration of New York Application October 27, 1942, Serial No. 463,559

6 Claims. (Cl. `2,61-90) .I f

This invention relates to improved fuel distributing means for internal combustion engines equipped with a supercharger. An object of the invention is to provide an improved means for uniformly injecting the fuelinto the intake airst'ream of a supercharger impeller.

Specifically, the fuel' is injected into the airstream at the supercharger impeller intake through a plurality of small holes in an annular spinner member rotatable with the impeller and disposed adjacent the impeller intake. The fuel is fed into the spinner member and the rotation of 'this member imparts a rotational velocity to the fuel. A plurality of baffles are provided within this member to `help rotate the fuel. As a result, the centrifugal force acting on the fuel injects the fuel into the airstream at the impeller intake through a plurality of small holes in the spinner. The baiiles Within the spinner are disposed so `as not to form separate compartments but instead to bridge across the annular chamber within `the spinner and leave a space between the bailles and outer circumference of this annular chamber. This disposition of the bailles permits equalization of the fuel level Within the i spinner,` thereby providing for uniform discharge of the fuel through the holes in the spinner.

.It has been found that engine performance can be improved by locating the constant pressure fuel discharge valve as close as possible to the point of discharge of the fuel into the impeller air' Accordingly, it is a further object of this invention to provide a constant pressure discharge valve which is designed to be located as close as possible t\o the point of discharge of the fuel into the airstream. v

Further objects of the invention will become apparent in reading the annexed detailed de scriptionin connection with the drawings, in which:

Fig. 1 is a diagrammatic side elevation of a radial cylinder aircraft engine with a portion of the supercharger housing broken away to broadly illustrate the invention;

Fig. 2 is an axial section through the supercharger and illustrating the impeller fuel inlector;

Fig. 3 is an enlarged sectional view of a portion of Fis. 2;

Fig. 4 is an axial section through a modification; y

Fig. 5 is an enlarged sectional view of a portion `of Fignlil carburetor to the intakeof the supercharger Fig. 6 is a perspective view of one of the spinner baffles; and

Fig. 7 is a perspective view of the spinner member used in the modification o f Figs. 4 and 5. 4

Referring to the drawings, a conventional radial cylinder aircraft engine is illustrated at II) having a carburetor or other device I2 for propor- V tioning the air and fuel. This carburetor may be similar to the pressure fuel-metering carburetor disclosed in Patent No. 2,165,447,\issued July 11,

1939, to K. A. Browne, or any other conventional device for metering the fuel in proportion to the air flow may be used. Intake air passes from the impeller I4 through transversely extending passage or intake duct I6. Fuel isrmixed with the air at the impeller intake in a manner hereinafter described and the impeller raises the pressure of the combustible mixture to the diffusing chamber I8 from which the `mixture is delivered to the various cylinders-2li through intake con- I duits 22. l

The supercharger is provided with a front housing wallA 23 and with a drive shaft 26. The drive shaft 26 extends through an opening in the rear wall 24 of the transversely disposed air intake duct I6. An oil seal sleeve 28 ls carried by the impeller shaft 26 and is provided with seal rings 30 cooperating with a bushing member 32 secured to said rear wall 24 of the intake duct I6. A fuel passage Y34, disposed within said rearwall 24, ex-

` tends from the carburetor I2 to the bushing I pressure while chamber 52 vis either vented to the vatmosphere as at 54 or may be connected to the member 32. An annular passage in the bushing 32 interconnects this fuel passage 34with a` passage38 leading to a constant pressure 4discharge valve indicated generally at 40. This valve is supported on the rear wall of the super-V charger housing and comprises a valve seat `42 and a movable valve member Il biased to a closed `positionby a spring'l. A flexible diaphragm 48l is secured to the movable valve member M and divides the valve housing into chambers 50 and 52. Valve chamber 50 is subjected to the fuel venturi suction of the carburetor in order to compensate for changes in fuel flow.' ingly, the flexible diaphragm 43 operates to control the position of valve member 44 in response to variations in fuel pressure to maintain asubstantially constant fuel pressure in the' chamber Accordcooperation with valve seat |20. The other end of the valve member ||8 extends into an annular spectively. From the annular space 62 the fuel Y flows to an annular chamber'12 in the spinner. The outer wall of this chamber is curved in an axial direction and a plurality of holes 14 extend through the spinner along themaximum circumference of the chamber 12. These holes communicate with the airstream just in front of the impeller I4. Also, a plurality of circumferentially disposed baffles 16 bridge the annular space I2 in `the spinner in such a manner as to leave a clear- {ance space between the outer edge of each baille member and the outer wall of the annular chamber 12. Annular spacing members 18 and 80 bev tween the spinner 64 and sleeve 28 maintain the spinner tightly against the hub of the impeller for rotation therewith.

In operation, rotation of the spinner member and its associated bailie's 16 impart a rotational velocity to the fuel in the annular chamber 12 and asr'a -result the centrifugal action on the fuel vejects the fuel through the plurality of holes 14. 'Ihe clearance between each baille and the outer wall'of the annular chamber 'I2 permits the fuel level to equalize' about this annular chamber. If,

jing'of the fuel may occur between the valve and the point of discharge of the fuel into the airstream with a resulting discontinuous fuel flow.

In the modification illustrated in Figs. 4 and 5,

" the general arrangement is similar to that illustrated in Figs. l, 2 and 3 except that the constant pressure discharge valve has been designed'to permit a much closer location of the valve to the spinner member. In this modification, aV supercharger is provided with a transversely extending air intake duct through the rear wall I 02 of which an impeller drive shaft. |04 extends.

lThis rear wall |02 of the air intake duct is pro- 'vided withV a bushing member 05 which cooperates with an oil seal sleeve |06 having sealY rings |08 carried by the impeller drive' shaft |04 and cooperating with the bushing |05. A fuel passage I |0 extends through the rear wall of the air intake duct from a suitable fuel metering carburetor or other device for metering the fuel in proportion to the air. An annular cap ||2Yis secured to the rear wall ofthe air intake duct about the bushing-|05 to form a continuation I4 of the fuel passage I0 and to. form an annular valve chamber ||6 about the bushing member |05. An annular slide valve member ||8 is slidably mounted on the bushing |05 and has one end extending into the valve chamber IIS for space |22 between the bushing |05 and the hub of the rear wall |02. An annular flexible dial phragm |24 has its inner end secured to the valve member I8 by suitable means, not shown, and has its outer end secured between the cap ||2 and the wall |02. A-spring |26 is disposed within the chamber |22 and biases the valve member toward its closed position against the fuel pressure on the other side of the diaphragm. The chamber |22 is vented to the atmosphere or is con- Vnected to the venturi suction in the carburetor through passage |28. The valve IIB is thereby operative to automatically maintain a substantially constant predetermined fuel pressure ln the `chamber IIB. A packing ring |30 between the cap ||2 and a shoulder on the bushing |05 provides an adequate seal for the ,chamber H5.

The valve ||6 discharges the fuel into a plurality of passages |32 in the bushing which passages feed the fuel into the annular space |34 between the bushing |04 and the annular member |36. This annular member |36 is disposed between the oil seal sleeve |06 and a spinner member |38 to secure the spinner member against the hub of the impeller |00 for rotation therewith. In this modification the spinner member I 38 overlaps the bushing member |05, and a seal ring |40 is provided between these members. The fuel'is fed from the annular space |34 into the annular chamber |42 within the spinner, and the bridge type baffles |44 help impart a rotational velocity to the fuel to cause ejection of the vfuel by centrifugal force through a plurality of holes Y|46 disposed along the maximum circumference of the annular chamber |42. Y

The spinner member with its baiiles is essentially the same in both modifications. This spinner member is best seen in Fig. '7 whichv is a perspective view of the spinner illustrated in Figs. 4 and 5 while Fig. 6 is a perspective view of one of the baliles. However, it seems obvious that the baffles may be formed or cast integral with the yspinner member.

help impart a rotational velocity to the fuel and these baliies, are disposed inwardly of the maximum circumference of the annular chamber within the spinner while the discharge holes are located along the maximum circumference. This construction insures an'even or symmetrical fuel level within the spinner so that a uniform fuel discharge is obtained. .Also, in both modifications the constant pressure fuel discharge valve is located close to the spinner member s'o that a short fuel path is provided between this valve and the ,point"of"discharge from the spinner. This location of the discharge valve minimizes any boiling u V'of the fuel as'a result of the low pressure existing between the discharge valve-and the point ofk discharge of .thefuel into the airstream. Any such boiling of the fuel tends to cause a discontinuous flow of fuel due to the presence of fuel vapor.

Accordingly, it is seen that this invention provides for a more uniform mixture of air and fuel than heretofore attainable.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifica- 'member having a plurality of openings through which fuel is discharged in front of said impeller.

2. In an internal combustion engine,an annular supercharger impeller, an impeller drive shaft, said impeller having an annular` intake opening about said drive shaft, an impeller intake duct transversely disposed across the axis of said impeller, said drive shaft extending through a wall of said duct, an annular fuel chamber in said wall about said drive shaft,v an annular spinner member disposed about the impeller shaft adjacentsaid impeller and arranged for rotation therewith, said spinner member providing an annular chamber about said impeller shaft, and an annular automatically operable fuel-pressure-regulating valve disposed about said impeller shaft for controlling the flow of fuel from said first mentioned chamber to said second mentioned chamber, said spinner member having a plurality of circumferentially spaced `holes through which fuel is discharged from its annu- Y lar chamber in front of the impeller.

` 3. In an internal combustion engine, an annular supercharger impeller, an impeller drive shaft, said impeller having an annular intake opening about said drive shaft, an impeller air intake duct transversely disposed across the axis of said impeller, said drive shaft extending through a Wall of said duct, an annular fuel chamber in said wall about said drive shaft, and an annular fuel pressure regulating valve disposed about said drive shaft and automatically operable to control the flow of fuel from said chamber into said air intake duct.

4. In an internal combustion engine, an annular supercharger impeller, an impeller drive shaft, and an annular fuel control valve concentrically disposed about said drive shaft, said valve being automatically responsive to the `fuel inlet pressure thereto for controlling the discharge of fuel into the impeller airstream.

5. In an internal combustion engine, an annuv lar supercharger impeller for the engine induction system, a fuelrcontrol valve concentrically Y, disposed directly in front of said impeller, and

means automatically operable in response to the fuel inlet'pressure to said valve for regulating the` discharge of fuel therefrom and into the impeller airstream. l

6. In an internal combustion engine, an annular supercharger impeller having an annular intake opening, a spinner member co-axially secured to said impeller for rotation therewith and providing a fuel chamber infront of said impeller, and a f uel pressure regulating` valve dis-` 

